Porthole aquarium stand



FIG. 1 is a perspective view of a porthole aquarium stand showing my invention;

FIG. 2 is a front view of FIG. 1; and,

FIG. 3 is a front view of FIG. 1 showing the enclosed cabinet's hinged door in the open position.

Portions of the porthole aquarium stand shown in broken lines form no part of the claimed design. 

CLAIM The ornamental design for a porthole aquarium stand, as shown and described. 